This present invention relates to a text editing device having a function for displaying text data under preparation and relational data corresponding to the position on a display, for example, a scale line corresponding to a print pitch when the text data are printed, or a numeral representation corresponding to a volume of data stored in memory or a volume of data capable of being stored, i.e. a memory space remaining for an additional storing of data.
As disclosed, for example, in U.S. Pat. No. 73729 (filed on Jul. 15, 1987), this kind of a device displays a cursor indicating a position where data is inputted on text data displayed on a display and a scale cursor on a scale line indicating a character position of a print out corresponding to this cursor position.
With this text editing device, for example a word processor, an operator can prepare a text while confirming a character position in printing for the effective preparation of the text. Since, however, the scale cursor is conventionally shifted each time the cursor is shifted, a longer period of time is necessary to shift the cursor, and thus when character data or a cursor shift instruction is inputted at a high speed by operating a keyboard at a high speed, a problem arises in that the cursor cannot be shifted corresponding to the input operations and sometimes the data cannot be inputted at the high speed.
Further, in the word processor it is required that a cursor displayed on a display screen is smoothly and quickly moved in case a space repeat mode is selected, that is, the cursor must be quickly moved in response to a successive input operation of a space code or a back-space code.
More specifically, this text editing device is arranged so that data inputted through the keyboard is temporarily stored in a buffer and the buffered input data is sequentially read out to be subjected to processing corresponding to the input data, and thus when the device takes a long time to effect the processing for shifting the cursor, the speed for reading out the input data from the buffer is lowered. Then, when data is stored in the buffer at a high speed by operating the keyboard at a high speed, much data is accumulated in the buffer and additional data cannot be inputted due to saturation of the buffer.
Further, in the word processor having the function for storing a plurality of character data and space data and the like and displaying a numeral representation corresponding to the volume of data being stored in a memory or capable of being stored in a memory, it is required that the numeral representation is varied in response to a variation of the volume of data caused by a successive input operation of data. Since the time for the calculation processing required for varying numeral representation is wasted, the movement of the cursor on the display screen ceases during each input operation of data, therefore, the cursor movement operation is discontinuously executed and the space repeat operation is not smoothly and quickly executed. The above disadvantage obviously appears in case a liquid crystal display unit having a long response time for represent operation is employed as a display unit, or the complicated calculation processing is employed for processing a large volume of data. Further, it is impossible for an operator of the word processor to separately discriminate each varying of the numeral representation even if the successive move operation of the cursor is able to be executed.